Columbia Little Kid/Big Kid Aquatooth Sandal 100% Mesh and synthetic Rubber sole Stretch, open-hole mesh upper for complete drainage and 360-degree ventilation Supportive, quick-drying synthetic overlays with webbing straps Removable, molded, perforated EVA insole with Omni-Fresh anti-bacterial and AgION anti-odor treatment Dual density molded EVA midsole with drainage holes Non-marking Omni-Grip rubber compound outsole with aggressive lug tread pattern and drainage holes